You believe that FTL travel is logical and implies ‘hard’ science fiction.

You think populating all alien planets with human-like, intelligent, spacefaring peoples, but giving them different cultures, is good creature building.

You think that sound actually travels through the vacuum of space and so your characters can hear distant explosions through the hull of a ship.

You think that info-dumping in science fiction is normal. Alternately, you believe that it’s okay to confuse the reader by using science that most people wouldn’t understand in such a way that the reader still doesn’t get it.

You can’t take criticism of your science or of your story itself.

You think it’s okay for your main character to be completely awesome and not have flaws.

You believe that your family will be completely honest with you about your writing. Alternately, you think your non-writing, non-reading friends can actually give you worldly advice.

You are under the impression that future technology will be perfectly beautiful and not be subject to Murphy’s Law.

Fantasy:

You think your fantasy story is 100% original right down to the very characters within the story.

You can’t take criticism of your work, which will be a lot.

You think that just because it is fantasy you can make up anything and expect it to be okay. You think that fantasy doesn’t have to be realistic.

You think info-dumping fantasy is acceptable writing behavior.

You think that your lively culture of little people is not going to be compared to Hobbits.

You believe that your story is better than anything Tolkien could ever come up with.

You believe Peter Jackson will turn your unpublished novel into a blockbuster movie.

You’re under the impression that fantasy is not derivative by nature.

You think your main character can be completely awesome and not have flaws.

You believe that your family will be completely honest with you about your writing. Alternately, you think your non-writing, non-reading friends can actually give you worldly advice.

You believe that your main character doesn’t have to deal with some sort of conflict and instead can go around being happy and not do anything important.